1,5 or 8‑11 Universal Thread: This core drill has a 5 or 8‑11 universal thread for easy and quick assembly to a standard fixed core or hand held drill press. It also works on various devices. 2,Innovative Design: Our diamond wet core bits feature chip evacuation holes, highly regular serrations and a concentric shaft design. 3,Alloy Steel, Diamond: This diamond core drill is composed of excellent alloy steel components, and diamond abrasive grains ensure longer core life. 4,Dry and Wet Drilling: Core drills are available for both dry and wet drilling to suit your job needs. Drill holes from a vertical position and add a little water can extend the life. 5,Scope of Application: Our core drilling bit is used to drill concrete, red brick, marble and other materials for installations such as air conditioning, plumbing, stair railings, highways and airports. Note: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement.